Early diagnosis of Parkinson’s disease possible via skin testing

Early diagnosis of Parkinson’s disease possible by a test that detects the presence of a protein called, alpha-synuclein in skin biopsy

A new test uses highly sensitive technology to detect the presence in the skin of “misfolded” alpha-synuclein (α-Syn) proteins that are the cause of nerve cell dysfunction and death in PD.

Skin testing offers several advantages over existing diagnostic procedures.

It is much less invasive than the current most effective method which analyzes the cerebrospinal fluid, the liquid surrounding the brain and spinal cord. Obtaining CSF requires a needle insertion into the spinal column while a skin biopsy is done with a small hollow punch inserted less than one inch into the skin of the neck or legs.

AS the α-Syn proteins begin accumulating 10-20 years before symptoms appear, the testing could help identify people long before symptoms appear

Brain imaging and certain blood tests can also be currently used to help diagnose PD, but they are not fully accurate or sensitive.

Physical changes associated with PD (including tremors, difficulty walking and speech problems) are debilitating. As the α-Syn proteins begin accumulating 10-20 years before these symptoms appear, the testing could help identify people long before symptoms appear.

“Ascertaining the presence, volume, and dispersion of the misfolded α-Syn proteins in more accessible specimens such as the skin can also be used for monitoring the progression of the disease and evaluating the effectiveness of new treatments,” said Wenquan Zou, MD, PhD,  an associate professor in the departments of Pathology and Neurology and associate director of the National Prion Disease Pathology Surveillance Center at Case Western Reserve School of Medicine.

In their preliminary study, researchers found that an ultrasensitive test (RT-QuIC) detected misfolded forms of α-Syn in autopsied skin tissues of PD patients with very high specificity and sensitivity. The samples were then sent to a lab for examination with another test (PMCA), by which scientists observed that skin α-Syn was detectable by PMCA too in PD patients but not in non-Parkinson’s controls – thereby confirming accuracy. A new research will expand on earlier efforts by studying a significantly larger number of patients.

“We are hopeful that our findings will pave the way for painless, accurate, and early detection of a series of devastating neurodegenerative diseases that are sure to escalate in number as the aging of the population continues and individuals live longer with chronic diseases,” added Zou.